Question

In Michelson’s interferometer 100 fringes cross the field of view when the movable mirror is
displaced through 0.02948 mm. calculate the wavelength of monochromatic light used.

Answer 1

Given :

Mirror move by distance, d = 0.02948 mm

Number of fringes appearing at the centre, N = 100

To find :

The wavelength of monochromatic light used.

Solution :

We know that, in Michelson’s interferometer wavelength is given by formula

λ = 2d / N

λ = 2×0.02948 mm / 100

= 0.05896 / 100

λ = 0.5896 × 10^-3 mm